How to Draw Mechanisms

Q. Which of the following statement(s) is/are true?
POS - Plane of symmetry
COS - Centre of symmetry

1. Stereoisomers containing exactly opposite R-S configurations with POS or COS, are identical.
2. Stereoisomers containing opposite R/S configuration without symmetry in molecule, are diastereomers.
3. If few wedge bonds (not all) are converted into dash bonds in an optically active molecule, then they are diastereomers.

4. Stereoisomers which are not mirror images are enantiomers.

Q. Which of the following compounds may not exist as enantiomers ?

1. $C{H}_{3}CH\left(OH\right)C{O}_{2}H$
2. $C{H}_{3}C{H}_{2}CH\left(C{H}_3\right)C{H}_{2}OH$
3. $C_6{H}_{5}C{H}_{2}C{H}_3$
4. $C_6{H}_{5}CHClC{H}_3$

Q. Two possible stereo-structures of $C{H}_{3}CHOHCOOH$ which are optically active are related as:

1. Atropisomers
2. Enantiomers
3. Mesomers
4. Diastereomers

Q. Match List - I with List II and select the correct answer using the code given below the lists.

List -I	List -II
A. Meso compounds	1. An equimolar mixture of enantiomer
B. Enantiomers	2. Stereoisomers that are not mirror images
C. Diastereoisomers	3. Non superimposable mirror images
D. Racemic mixture	4. An optically inactive compound whose molecules are achiral even though they contain chiral centre

1. $$\begin{array}{cccc}A& B& C& D\\ 3& 4& 1& 2\end{array}$$
2. $$\begin{array}{cccc}A& B& C& D\\ 3& 4& 2& 1\end{array}$$
3. $$\begin{array}{cccc}A& B& C& D\\ 4& 3& 1& 2\end{array}$$
4. $$\begin{array}{cccc}A& B& C& D\\ 4& 3& 2& 1\end{array}$$

Q. Identify number of nucleophilic substitution reactions in the given reactions?

Q. i) Involves complete shifting of $\pi$ electrons.
ii) It is a temporary effect.
iii) In -E effect , $\pi$ electrons of the multiple bond are transferred to the atom to which the reagent gets attached.
iv) It operates in organic compounds having multiple bonds under the influence of an outside attacking species.
How many statements are correct regarding Electromeric effect from above.

Q. How many of the following given molecules are aromatic in nature

Q. in nucleophilic substitution reaction in chloro benzene why ewg at para and ortho position increases reactivi

Q. _______are found on the left to middle of The Periodic Table .

Q. Which of the following is not a metalloid?

Q.

What do you understand by a lone pair of electrons ?

Q. The number of sigma $\left(\sigma \right)$ and $\left(\pi \right)$ bonds present in $1,3,5,7$-octatetraene are __________ respectively.

1. $15$ and $4$
2. $16$ and $3$
3. $14$ and $3$
4. $16$ and $5$
5. $17$ and $4$

Q. Ordinarily the barrier to rotation about a carbon-carbon double bond is quite high but compound A was observed by NMR to have a rotational barrier of only about 20K cal/ mole is due to:

1. double bond having partial triple bond character because of resonance
2. +I effect of $n{C}_3{H}_7$ groups makes double bond having partial single bond character.
3. double bond undergo flipping
4. double bond having very high single bond character becauyse of aromaticity gained in both 3 & 5 membered ring.

Q. The decreasing order of stability of following cations is

1. P>Q>R>S
2. Q>P>S>R
3. Q>P>R>S
4. Q>S>R>P

Q. Tertiary alchols $\left(3^o\right)$ having atleast four carbon atoms upon drastic oxidation yield carboxylic acid with:

1. One carbon atom less
2. Two carbon atom less
3. All the above three option are correct
4. Three carbon atom less

Q. Phenol and carboxylic acid can be distinguished by the reagent

1. Both (a) and (b)
2. $NaH{CO}_3$
3. $Na$
4. None of these

Q. Match List - I with List II and select the correct answer using the code given below the lists.

List -I	List -II
A. Meso compounds	1. An equimolar mixture of enantiomer
B. Enantiomers	2. Stereoisomers that are not mirror images
C. Diastereoisomers	3. Non superimposable mirror images
D. Racemic mixture	4. An optically inactive compound whose molecules are achiral even though they contain chiral centre

1. $$\begin{array}{cccc}A& B& C& D\\ 3& 4& 1& 2\end{array}$$
2. $$\begin{array}{cccc}A& B& C& D\\ 3& 4& 2& 1\end{array}$$
3. $$\begin{array}{cccc}A& B& C& D\\ 4& 3& 1& 2\end{array}$$
4. $$\begin{array}{cccc}A& B& C& D\\ 4& 3& 2& 1\end{array}$$

Q. Two possible stereo-structures of $C{H}_{3}CHOHCOOH$ which are optically active are related as:

1. Atropisomers
2. Enantiomers
3. Mesomers
4. Diastereomers

Q. (I) Draw the resonating structure of $C_6{H}_5{NO}_2$ and $C_6{H}_{5}OH$.
(II) Why ${\left({CH}_3\right)}_3{C}^{+}$ carbocation is more stable than ${CH}_3$?

Q. Chlorination in the given produces a chiral carbon. Indicate the compounds:

Q. Which would undergo S_N2 reaction faster in the following pair and why ?
CH_​3-CH₂-Br and CH₃-CH₂-I

Q. Fill in the blanks:
In the formation of salicyclic acid by Reimer-Tiemann's reaction, phenol is heated with _________ in presence of an alkali.

Q. Arrange the following in decreasing order of enol content.
i) Diethyl malonate
ii) Acetoacetic ester (AAE or EAA)
iii)Acetyl acetone
iv) $PhCOC{H}_{2}COC{H}_3$

1. iv > iii > ii > i
2. iv > iii > i > ii
3. iii > iv > ii > i
4. iii > iv > i > ii